For almost as long as there have been computers, people have tried out ways of creating origami—or at least, folded paper shapes—using computational techniques. Once they began developing computational tools for folding, there arose the supporting field of computational origami: the study of mathematical laws and data structures that apply to the intersection of computing and folding. Computational origami is a subset of the branch of computer science known as computational geometry; many of the algorithms of the former have broader applicability in the latter. We see, for example, the straight skeleton appearing in problems as diverse as the design of origami insects and the design of pitched roofs on buildings! The practical realization of computational origami theory and algorithms are tools—computer programs — that carry out origami design and computations (more informations in http://www.langorigami.com/science/computational/computational.php).